JP4114011B2 - Refrigeration cycle apparatus and receiver used therefor - Google Patents

Description

  The present invention relates to a refrigeration cycle apparatus such as an air conditioner and a refrigeration cycle using a refrigeration cycle, and a receiver used therefor, and in particular, a CFC or HCFC refrigerant, and a refrigerant using mineral oil as a refrigerator oil to an HFC refrigerant. It is suitable for those that are replaced with those using refrigeration oil for HFC.

  CFC-type refrigerant or HCFC-type refrigerant, HFC-type refrigerant that is not compatible with mineral oil from an air conditioner that uses mineral oil as refrigerating machine oil (old machine), and an air-conditioner that uses HFC refrigerating machine oil (new machine) When the connection pipe that connects the indoor unit and the outdoor unit is reused when the replacement is performed, pollutants (impurities) remain in the reused connection pipe. This impurity is insoluble in the HFC refrigerant used in the new machine, or is a weakly soluble component of refrigerating machine oil (mineral oil, alkylbenzene, etc.) enclosed in the old machine, oxidative degradation reaction product of the refrigerating machine oil, oxidation scale, chlorine compound Etc.

In the method using the existing pipe, the refrigerating machine oil in the new machine deteriorates due to impurities remaining in the connection pipe. Furthermore, components that do not dissolve in the refrigerant may precipitate in the low temperature portion of the refrigeration cycle, clogging the refrigeration cycle, and may significantly impair the reliability of the air conditioner.
Therefore, it is known to perform a cleaning operation for collecting impurities remaining in the connection pipe when using the existing pipe, which is described in Patent Document 1, for example.

JP 2000-9368 A

  In the above prior art, the foreign matter capturing means is disposed between the user side heat exchanger and the compressor at a position that becomes a gas refrigerant. I had to pass through several times. Therefore, after replacing the old machine with the new machine, it is necessary to carry out the cleaning operation in the connection pipe for a relatively long time, for example, for about 1 to 2 hours. In other words, the work time for air conditioner replacement work and renewal work was inevitably long. In particular, in the case of multi air conditioners for buildings, the refrigerant pipes are not only long, but they are complex and contain many branch pipes to indoor units connected to multiple units. Recovery was difficult.

  An object of the present invention is to efficiently collect impurities remaining in a reused connection pipe in a tank, enable renewal work in a short time, and improve reliability and performance.

  Another object of the present invention is to simplify the structure of a tank for collecting impurities, to improve productivity, to be small and compact.

In order to solve the above problems, the present invention provides a refrigeration cycle apparatus in which a compressor, a heat source machine side heat exchanger, an expansion device, and a use side heat exchanger are sequentially connected, from the heat source machine side heat exchanger to the use side. A receiver that stores liquid refrigerant while reaching the heat exchanger, a filter that is provided in the receiver, and a refrigerant that is arranged so that the tip protrudes from the filter toward the bottom of the receiver and introduces or leads out the refrigerant. An inlet / outlet pipe and a strainer provided at the tip of the refrigerant inlet / outlet pipe, and the filter is sandwiched by an oscillator having a plate-like top and bottom and a corner bent, and the spring property of the claw The filter is arranged in the receiver with a gap from the inner wall .

Further, in the above, the filter is configured by laminating a plurality of thin disk-like objects having the same shape in the piping direction of the refrigerant inlet / outlet pipe, and the number of the laminated layers is the capacity of the receiver. Or it is desirable that it is determined according to the required capacity of the filter built in the receiver .

Furthermore, another feature of the present invention is a receiver that stores liquid refrigerant of a refrigeration cycle device in which a compressor, a heat source device side heat exchanger, an expansion device, and a use side heat exchanger are sequentially connected, and has a filter inside. And a first assembly part having a pair of refrigerant inlet / outlet pipes for introducing or deriving the refrigerant and an upper cap of the receiver, and an oscillator that has a plurality of filters stacked and plate-like upper and lower tabs and corners bent. And a third assembled part in which the lower cap of the receiver and the body are welded together, and the filter has an inner wall in the receiver due to the spring property of the claw of the oscillator. It exists in being arranged with a gap .

  According to the present invention, since the mineral oil is captured by the filter using the difference in viscosity in the tank at the position that becomes the liquid refrigerant, the mineral oil is reliably captured, and the deterioration of the refrigeration oil for HFC is suppressed. Can do.

  In addition, when the filter is built in the tank that collects impurities, the refrigerant inlet / outlet piping penetrates the filter, so the structure of the tank is simplified, the productivity of the tank and refrigeration cycle equipment is good, and it is compact and compact. Can be made.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
A method for recovering the refrigerant insoluble component remaining in the existing piping or the weakly soluble component with respect to the refrigerant will be described. Hereinafter, the refrigerant insoluble component remaining in the existing piping will be described as mineral oil.
When an air conditioner using a CFC or HCFC is aged, the outdoor unit and the indoor unit that are air conditioners are exchanged. That is, the CFC or HCFC refrigerant is recovered, and the outdoor unit 11 or the outdoor unit 11 and the indoor unit 20 are replaced with those shown in FIG. The liquid connection pipe 7 and the gas connection pipe 8 are reused from the old machine. Since the outdoor unit 11 is preliminarily filled with HFC, the block valves 6 and 9 are closed and the indoor unit 20, the liquid connection pipe 7 and the gas connection pipe 8 are evacuated, and then the blocking valve 6 and 9 are closed. Alternatively, the stop valves 6 and 9 are opened and the HFC is additionally charged.

  In the case of cooling operation, the high-temperature and high-pressure gas refrigerant compressed by the compressor 1 is discharged from the compressor 1, and the gas refrigerant flows into the heat source side heat exchanger 3 through the four-way valve 2, where heat exchange is performed. To condense. The condensed and liquefied refrigerant passes through the fully expanded first expansion device 4, the excess refrigerant is stored in the tank 5, and the remaining is sent to the indoor unit 20 through the blocking valve 6. The sent liquid refrigerant flows into the second expansion device 21, where it is decompressed to a low pressure to become a low pressure two-phase state, and exchanges heat with the use side medium such as air in the use side heat exchanger 22 to evaporate / Gasify. Thereafter, the gas refrigerant returns to the compressor 1 through the blocking valve 9, the four-way valve 2, and the accumulator 10.

  In the case of heating operation, the high-temperature and high-pressure gas refrigerant compressed by the compressor 1 is discharged from the compressor 1 together with the refrigeration oil for HFC, and flows into the use side heat exchanger 22 through the four-way valve 2 and the blocking valve 9. Heat exchange with the use side medium such as air to condense. The condensed and liquefied refrigerant flows into the blocking valve 6 and the tank 5, is decompressed by the first expansion device 4, and is evaporated and gasified by exchanging heat with a heat source medium such as air and water in the heat source unit side heat exchanger 3. . The evaporated and gasified refrigerant returns to the compressor 1 through the four-way valve 2 and the accumulator 10.

  Mineral oil hardly dissolves in HFC-based refrigerants (such as R410A), while it dissolves in refrigeration oils for HFC (such as ether oil). And mineral oil is not isolate | separated in the compressor 1 with many HFC refrigerating machine oil, but isolate | separated within the liquid connection piping part 7 and tank (receiver) 5 with many liquid refrigerants.

  A filter 54 is provided in the tank 5 and is a fibrous material having a relatively large number of meshes. The fiber is made of at least one of polyester and polypropylene. The liquid refrigerant and the HFC refrigerating machine oil dissolved in the liquid refrigerant are liquids having a low viscosity, whereas the mineral oil is a liquid having a significantly higher viscosity than the liquid refrigerant and the HFC refrigerating machine oil dissolved in the liquid refrigerant. Therefore, the liquid refrigerant and the refrigeration oil for HFC dissolved in the liquid refrigerant pass through the filter 54, whereas the mineral oil is caught between the fibers of the filter 54 having a large mesh number, and is then trapped inside the fibers by capillary action. In addition, when deteriorated mineral oil is mixed in the refrigerating machine oil, the deterioration of the refrigerating machine oil is accelerated, and the higher the temperature, the more the deterioration tends to be accelerated. However, the mineral oil is separated and captured in the tank 5 in which the filter 54 is disposed. It is possible to separate the mineral oil deteriorated in the above from the high-temperature compressor, and to suppress the deterioration of the refrigerating machine oil, thereby improving the reliability of the system.

  FIG. 10 shows a procedure for assembling the tank 5, and the lower right diagram and FIG. 1 show a state where the tank 5 is assembled.

  First, the cap 53b, the refrigerant inlet / outlet pipe 51, and the strainer 52 are integrated together as shown in the upper left diagram of FIG. 10, and the stack of the filters 54 is integrated together as shown in the upper right diagram. As shown in the left figure, the body 53a of the tank 5 and the cap 53c at the bottom of the tank 5 are used as an integral assembly part. Since the tank 5 is assembled after the three integrated parts are assembled, the body 53a and the cap 53c under the tank 5 can be welded before the filter 54 is built in the body 53a. It is possible to prevent the 54 fibers from being deteriorated by heat. Also, by not assembling the filter 54 as a component until the number of integrated integrated parts becomes 3, the filter 54 can be prevented from being deteriorated due to dirt and moisture absorption, and the reliability is further improved. Handling during assembly is easy and productivity can be improved.

  FIG. 2 is a plan view of the tank 5, and FIG. 3 shows a state in which the filter 54 is configured in a layered manner in the tank 5, and the filter 54 is a disc-shaped object having the same shape in the piping direction of the refrigerant inlet / outlet pipe 51. Are stacked. The number of layers to be stacked is determined according to the capacity of the tank 5 or the required capacity of the filter 54 built in the tank 5. Therefore, it is possible to cope with different capacities by the elements of the filter 54 having the same shape, and the mass productivity of the filter 54 can be improved and the price can be reduced.

  FIG. 6 shows an oscillator 55 for storing the filters 54 stacked in the tank 5. As shown in the plan view of FIG. 2, the oscillator 55 is rectangular when viewed from above, and the apex of the body 53 a is shown. It is bent so that four points are in contact with the inner periphery, and each is fixed with springiness. Therefore, the filter 54 is fixed so that it does not move in the vertical and horizontal directions even if there are vibrations due to transportation, pressure fluctuations in the refrigeration cycle, and the like by the oscillators 55 provided above and below the filter 54. Further, since the filter 54 is vibrated to prevent the filter 54 from moving in the vertical direction, breakage and unraveling of the filter 54 fibers are prevented, and reliability is improved.

  In addition, even if the shape of the refrigerant inlet / outlet pipe 51 is deformed, the filter 54 does not come into contact with the body 53a. Similarly, contact with the body 53a can be avoided during assembly, and productivity can be improved. it can. And since the contact part of the filter 54 and the oscillator 55 has a spring property as a nail | claw, it becomes easy to make the clearance gap between the filter 54 and the body 53a uniform.

  FIG. 4 shows an enlarged view of a mesh-structured strainer 52 portion attached to the tip of the refrigerant inlet / outlet pipe 51, and has a tapered shape where the tip becomes smaller than the refrigerant inlet / outlet pipe 51 side. The pipe inner diameter of the refrigerant inlet / outlet pipe 51 determines a necessary inner diameter (inner area) from the refrigerant circulation amount assumed by the refrigeration cycle, etc. The area of the mesh structure and the screen opening area are determined by the refrigerant inlet / outlet pipe 51. The strainer 52 is exposed (protruded) from the refrigerant inlet / outlet pipe 51 so as to be three times or more the inner area of the refrigerant. Thereby, even when the fibers of the filter 54 are clogged, the amount of circulation necessary for the device can be secured.

  Further, surplus refrigerant accumulates in the liquid state in the tank 5 in accordance with the operation state of the refrigeration cycle, so that the refrigeration cycle is stabilized. At this time, the liquid refrigerant accumulates from the bottom of the tank 5. Therefore, even when the strainer 52 is provided at the lowermost part of the tank 5 and the fibers of the filter 54 are clogged in the mesh portion of the strainer 52 due to the accumulation of the liquid refrigerant, the fibers of the filter 54 are at the liquid level of the liquid refrigerant. To rise to the liquid level. That is, due to the refrigerant flow pressure loss that occurs when the strainer 52 is disposed below the liquid level of the liquid refrigerant and the fibers of the filter 54 are removed from the strainer 52 by the refrigerant liquid and the strainer 52 is clogged. Prevent performance degradation.

  In addition, since a strainer 52 that is a mesh mesh strainer having a finer mesh than the fibers of the filter 54 is attached to the tip of the refrigerant inlet / outlet pipe 51, even if the fibers of the filter 54 are released, they are not discharged out of the tank 5. The fibers do not flow out together with the refrigerant and are not clogged in the middle of the refrigeration cycle, so that the reliability as an air conditioner is not impaired.

As a pressure vessel structure used for the refrigerant, the assembly of the body 53a and the caps 53b and 53c is joined by welding. And since welding temperature becomes very high temperature, it exceeds the maximum use temperature of filter 54, the fiber of filter 54 deteriorates with heat, and it becomes impossible to capture a refrigerant insoluble component. Therefore, a predetermined interval is provided between the body 53a and the filter 54 so that the temperature increase in the inner surface of the tank 5 of the body 53a, which becomes high due to welding, becomes equal to or lower than the maximum operating temperature of the filter 54.
FIG. 5 is a perspective view showing the relationship between the refrigerant 54 and the refrigerant inlet / outlet pipe 51. The filter 54 is provided with two holes, and the refrigerant inlet / outlet pipe 51 is inserted to penetrate the filter 54. The diameter of the filter 54 is smaller than the inner diameter of the tank 5 and is fixed by the oscillator 55, so that the filter 54 is fixed at a position where it is not in contact with the body 53a.

  Further, instead of opening the through hole in the filter 54, the shape may be provided with two notches as shown in FIG. According to this, workability is improved because the refrigerant inlet / outlet pipe 51 may be assembled as shown by the arrows in FIG. Further, as shown in FIG. 9, instead of the oscillator 55, plate-like members 56 and 57 are formed, the filter 54 is formed into a quadrangular prism shape, and the plate-like member 56 is orthogonal to the plate-like member 57. The sandwiching filter 54 may be fixed by arranging. This simplifies the shape of the filter 54 and facilitates assembly, which is convenient for reducing the price.

  As described above, by arranging the filter 54 in the tank 5, the mineral oil discharged from the compressor 1 together with the refrigerating machine oil for HFC is separated in the liquid connection pipe section 7 and the tank 5, and only the separated mineral oil is filtered. It becomes possible to capture at 54. When the compressor 1 is in the form of a high-pressure chamber system in which the pressure of the refrigerating machine oil reservoir in the compressor 1 is high, or when an oil separator is disposed in the discharge part of the compressor 1, the compressor 1 or the oil separator The temperature of the refrigeration oil stored in the tank becomes high. On the other hand, the temperature of the liquid connection piping part 7 and the tank 5 becomes lower than that temperature. The deterioration of the refrigerating machine oil is accelerated as the temperature rises, and the deterioration of the HFC refrigerating machine oil is further promoted as the mixing amount of the mineral oil (deteriorating oil) remaining in the existing pipe increases. By capturing the mineral oil in the tank 5 that is cooler than the inside or the oil separator, it is possible to suppress the deterioration of the refrigeration oil for HFC.

  Further, a strainer 52 finer than the filter fiber is provided at the tip of the refrigerant inlet / outlet pipe 51 provided in the tank 5 (if the flow direction of the refrigerant can be specified, a strainer is provided at the pipe tip on the outlet side. Therefore, even when the fiber of the filter is broken, the reliability of the refrigeration cycle is not significantly reduced by the filter fiber, such as clogging of the refrigeration cycle and a decrease in efficiency. Further, the entire filter itself may be wrapped with a strainer.

  In addition, the strainer surface area should be at least three times the internal area ratio of the refrigerant inlet / outlet pipe so that a flow path equal to or greater than that of the refrigerant inlet / outlet pipe can be secured even when undissolved filter fibers accumulate at the strainer site. Since it is arranged at the lower part, even when the undissolved filter fiber is excessively accumulated in the strainer part, the filter fiber floats on the refrigerant liquid surface by the liquid refrigerant in the tank, and the strainer can be prevented from being clogged.

  Furthermore, since the refrigerant inlet / outlet pipe 51 in the tank 5 penetrates the filter 54 and does not directly contact the body of the tank 5, heat from the welding operation of the body and the cap portion at the time of manufacturing the tank is directly applied to the filter 54. Therefore, it is possible to prevent a decrease in the reliability of the filter 54 due to heat, and it becomes easy to manage the temperature of the filter 54 in the welding process. The shape of the filter that penetrates the refrigerant inlet / outlet pipe 51 may be a round hole or a notch, or may be in direct contact with the body of the outer container portion constituting the tank 5 by sandwiching and fixing the filter by two pipes. You can avoid it.

  Furthermore, even when the tank capacity changes due to the change in the longitudinal dimension of the body by stacking multiple filters of the same shape, the filter capacity can be adjusted to adjust the number of filter parts of the same shape. The tank mounting structure and filter parts can be shared.

  Furthermore, since the shape of the oscillator 55 that fixes the filter 54 is a shape that makes partial contact with the body of the tank 5 at three or four locations, the attachment position of the filter 54 can be easily held at the center, When the tank 5 is assembled, it is possible to easily manage the gap between the body and the filter 54 and insert the filter into the tank 5.

The front view of the receiver (tank) by one embodiment of the present invention. The top view seen from the upper surface of FIG. The receiver (tank) side sectional view by one embodiment of the present invention. The enlarged view of the front-end | tip part of the refrigerant | coolant entrance / exit piping by one Embodiment. The perspective view of the filter attachment part by one Embodiment. The receiver (tank) front view which shows the oscillator by one Embodiment. FIG. 4 is a cycle diagram illustrating an embodiment according to the present invention. The perspective view which shows the filter attachment part by other embodiment. Furthermore, the perspective view which shows the filter attachment part by other embodiment. The assembly explanatory view showing how to assemble a receiver (tank) by one embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Compressor, 2 ... Four-way valve, 3 ... Heat source machine side heat exchanger, 4 ... 1st expansion device, 5 ... Tank, 6, 9 ... Stop valve, 7 ... Liquid connection piping, 8 ... Gas connection piping, DESCRIPTION OF SYMBOLS 10 ... Accumulator, 11 ... Outdoor unit, 20a, 20b ... Indoor unit, 21a, 21b ... Second expansion device, 22a, 22b ... Use side heat exchanger, 51a, 51b ... Refrigerant inlet / outlet piping, 52a, 52b ... Strainer, 53a ... Body, 53b, 53c ... Cap, 54 ... Filter, 55a, 55b ... Oscillator, 56 ... Thunder, 57 ... Fixing plate.

Claims (3)

In the refrigeration cycle apparatus in which the compressor, the heat source side heat exchanger, the expansion device, and the use side heat exchanger are connected in sequence,
A receiver for storing liquid refrigerant between the heat source unit side heat exchanger and the use side heat exchanger;
A filter provided in the receiver;
A refrigerant inlet / outlet pipe for introducing or leading out a refrigerant, which is arranged so that a tip protrudes from the filter toward the bottom of the receiver;
A strainer provided at the tip of the refrigerant outlet pipe ,
The filter is sandwiched by an oscillator having tabs whose upper and lower sides are bent and corners are bent, and the filter is disposed in the receiver with an inner wall and a gap by the spring property of the tabs. Refrigeration cycle equipment. 2. The filter according to claim 1, wherein the filter is configured by laminating a plurality of thin disk-like objects having the same shape in the piping direction of the refrigerant inlet / outlet pipe, and the number of the laminated layers is determined by the receiver. Or a required capacity of a filter built in the receiver . A receiver that stores a liquid refrigerant of a refrigeration cycle device in which a compressor, a heat source device side heat exchanger, an expansion device, and a use side heat exchanger are sequentially connected, and has a filter therein,
A first assembled part having a set of refrigerant inlet / outlet pipes for introducing or deriving the refrigerant and an upper cap of the receiver;
A second assembled part sandwiched by an oscillator having a claw in which a plurality of the filters are stacked and the upper and lower sides thereof are plate-like and the corners are bent ;
A third assembled part in which the lower cap and body of the receiver are welded ;
And the filter is arranged in the receiver with an inner wall and a gap by the spring property of the claw of the oscillator .

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